The PBOC would allow such online payments to be reintroduced on a trial basis once related security and technical standards were in place, said the anonymous central bank official.

The online shopping boom has led to e-commerce leaders like Alibaba and Tencent scrambling to give customers a quick and convenient way to pay, such as payments by scanning a bar or QR code.

Alibaba and Tencent said earlier this month that they had joined China CITIC Bank to each issue one million online credit cards, only to be called off by the central bank two days later.

The central bank official attributed the suspension to concerns about multiple risks.

Technological and business models concerning payments via code scanning are only in the experiment stage, and there is no uniform technological and certification standards, the official said.

The official said substantial risks were in the "formation mechanism and transmission process" of the codes, lack of security guarantee for the payment terminals, and a shortage of protective tools for code verification.

In most countries, central banks, bank card associations and financial institutions are relatively cautious with payments via code scanning and there has been no widespread use of the payment model, he said.

The official also referred to a number of cases in China resulting from virtual payments where consumers, after code scanning, found their personal information had been leaked or money stolen from their account.

"With so many problems unanswered, the security risks would be unimaginable if code-scanning payments were adopted by hundreds of millions of users of payment companies," he warned.

Concerning virtual credit cards, the official pointed to the application process which has no strict risk control procedures or face-to-face qualification checking required by traditional banks.

"So, the anti-money laundering system and the real-name system for bank accounts are at risk of being damaged," he said.

Virtual credit cards are not allowed for now, also because of the lack of a uniform regulation governing the issuance of virtual and real credit cards, which might lead to unfair competition, the official said.

However, both virtual credit cards and code-scanning payments still have a future in China, but only after security concerns are addressed.

"It is suspension, not termination," the official stressed.

The PBOC would work with all relevant sides including the payment firms to evaluate the two business models in terms of technological security, consumer protection, fighting money laundering and real-name system, he said.

"We would take security as our bottom line and support the payment companies in improving business procedures and regulations. After the security concerns get addressed, they can conduct the business on a trial basis," he added.